feat(clients): implement client management actions and UI

- Added actions for creating, updating, and archiving client records in `actions.ts`.
- Created a new client management UI in `clients-client.tsx` to display and manage clients.
- Integrated client data fetching and state management in `page.tsx`.
- Updated layout to change fallback user name from "MindSpace Kullanıcısı" to "Cognis Kullanıcısı".

app/(dashboard)/clients/actions.ts

@@ -0,0 +1,119 @@
+"use server";
+
+import { createClient } from "@/lib/supabase/server";
+import { revalidatePath } from "next/cache";
+
+const CLIENT_STATUSES = ["active", "paused", "archived"] as const;
+
+function cleanText(value: FormDataEntryValue | null) {
+  const text = typeof value === "string" ? value.trim() : "";
+  return text.length > 0 ? text : null;
+}
+
+function readStatus(value: FormDataEntryValue | null) {
+  const status = typeof value === "string" ? value : "active";
+  return CLIENT_STATUSES.includes(status as (typeof CLIENT_STATUSES)[number])
+    ? status
+    : "active";
+}
+
+function cleanWebsite(value: FormDataEntryValue | null) {
+  const website = cleanText(value)?.replace(/\s/g, "") || null;
+
+  if (!website) {
+    return null;
+  }
+
+  return /^https?:\/\//i.test(website) ? website : `https://${website}`;
+}
+
+async function getCurrentUserId() {
+  const supabase = await createClient();
+  const {
+    data: { user },
+    error,
+  } = await supabase.auth.getUser();
+
+  if (error || !user) {
+    throw new Error("Müşteri işlemi için giriş yapmış kullanıcı bulunamadı.");
+  }
+
+  return { supabase, userId: user.id };
+}
+
+export async function createClientRecord(formData: FormData) {
+  const { supabase, userId } = await getCurrentUserId();
+  const name = cleanText(formData.get("name"));
+
+  if (!name) {
+    throw new Error("Müşteri adı zorunludur.");
+  }
+
+  const { error } = await supabase.from("clients").insert({
+    user_id: userId,
+    name,
+    company_name: cleanText(formData.get("company_name")),
+    email: cleanText(formData.get("email")),
+    phone: cleanText(formData.get("phone")),
+    website: cleanWebsite(formData.get("website")),
+    status: readStatus(formData.get("status")),
+    notes: cleanText(formData.get("notes")),
+  });
+
+  if (error) {
+    throw new Error(`Müşteri eklenemedi: ${error.message}`);
+  }
+
+  revalidatePath("/clients");
+}
+
+export async function updateClientRecord(formData: FormData) {
+  const { supabase, userId } = await getCurrentUserId();
+  const id = cleanText(formData.get("id"));
+  const name = cleanText(formData.get("name"));
+
+  if (!id || !name) {
+    throw new Error("Müşteri güncellemek için müşteri adı ve kayıt kimliği zorunludur.");
+  }
+
+  const { error } = await supabase
+    .from("clients")
+    .update({
+      name,
+      company_name: cleanText(formData.get("company_name")),
+      email: cleanText(formData.get("email")),
+      phone: cleanText(formData.get("phone")),
+      website: cleanWebsite(formData.get("website")),
+      status: readStatus(formData.get("status")),
+      notes: cleanText(formData.get("notes")),
+    })
+    .eq("id", id)
+    .eq("user_id", userId);
+
+  if (error) {
+    throw new Error(`Müşteri güncellenemedi: ${error.message}`);
+  }
+
+  revalidatePath("/clients");
+}
+
+export async function archiveClientRecord(formData: FormData) {
+  const { supabase, userId } = await getCurrentUserId();
+  const id = cleanText(formData.get("id"));
+
+  if (!id) {
+    throw new Error("Arşivlenecek müşteri bulunamadı.");
+  }
+
+  const { error } = await supabase
+    .from("clients")
+    .update({ status: "archived" })
+    .eq("id", id)
+    .eq("user_id", userId);
+
+  if (error) {
+    throw new Error(`Müşteri arşivlenemedi: ${error.message}`);
+  }
+
+  revalidatePath("/clients");
+}